Usage:
3116 ( 2BK, 7SF ) Truck Engines In 1990-91 C6H And C7H Topkick/Kodiak Chevrolet And GMC Trucks
Description of Change: A new hose is used to connect the turbocharger compressor outlet to the inlet tubing for the ATAAC. The former hose could develop a tear. The tear could allow compressed air from the turbocharger to escape. This could result in an audible high pitch whine and/or a loss of power. The former hose has a depressed area (dip) around the center of the hose. The new hose has a raised area (hump) around the center of the hose. See the illustration. The new hose uses a different manufacturing process that will help prevent the tears.
Typical cross section of former hose (1) and current hose (2).
Adaptable To: The new 15679504 Hose (GMC part number) is in effect on all vehicles built after the following GMC Vehicle Identification Numbers
- GMC Truck...1GDM7H1J8MJ512250
- Chevrolet...1GBJ7H1J9MJ106991
The new hump hose can be used to replace the former hose on earlier vehicles.
When replacing a former hose, be sure the new hump hose and ATAAC inlet tubing are positioned so that there is clearance between the tubing and the turbocharger outlet flange. Tighten the upper and lower constant torque clamps to a torque of 5.5 to 6.0 N·m (49 to 53 lb in).